I wont recommend to do spa here. First of all, they won't provide you with standard amenities (only one towel and thats all, no slippers, second towel, not even carry on to put your books etc). For the price you pay, there is no proper changing room (only can change in one toilet which was really really really dirty), and all furniture and things like that is outdated (the massage bed had a huge tear). And the bathtub is too small for two people. I spent more than 90usd for two people, 1,5 hours. We were not even allowed to use the normal swimming pool. Hotel itself, particularly the spa, needs an upgrade as its a bit moldy and dirty. Really? For a four star hotel facilities it's a quite a shame... Anyways to answer your question, they're open from 9-19 but please consider to do it at a better place.

Hire a local driver. Maybe 40-50 US dollars.